1. Field of the Invention
The present invention generally relates to sample-loading systems applied to the fields such as medical treatment, chemical industry etc. and, more particularly, to an anti-collision device and an anti-collision method thereof.
2. Discussion of the Related Art
Sample-loading systems are often used in medical treatment and chemical industry. Nowadays, the commonly adopted sample-loading systems are capable of automatically taking samples and loading the samples. In the process of movement (e.g., rotary movement or linear movement), the sample-loading system maybe collides with a person that is replacing a sample or a reagent, or collides with other objects. Also, a manipulative error maybe causes the sample-loading system to collide with other equipments. Either of the above-mentioned collisions can result in damages to the sample-loading system and errors in the test result. What is more serious is that the collision maybe causes injuries to the person. In order to ensure safeties of the person and apparatus, it is necessary to successfully detect the collisions occurring in the process of the movement of the sample-loading system. At present, for a rotary sample-loading system, the following three solutions are employed to detect the collisions occurred in the process of rotation.
The first solution is pressure detection. Specifically, a pressure sensor is placed at positions apt to be collided to detect changes of pressure value so as to judge whether the collision occurs. The shortcomings of the pressure detection are that the size of the drive portion is increased and the weight of the moving mechanism is also increased simultaneously. Moreover, the provision of the sensors also enhances the cost of the product (i.e., the sample-loading system with the sensors).
The second solution is acceleration detection. At the time when the sample-loading system is normally rotating, it has constant acceleration curves at stages of accelerating movement, uniform movement and decelerating movement. Through comparing the acceleration curve during rotating with that exhibited at normal working state, it is able to judge whether the collision occurs according to the curve difference therebetween. This solution needs to correctly distinguish the situation of a collision from that of a vibration generated when the sample-loading system accelerates at the start and decelerates at the end. Therefore, it is necessary to compare the signal detected by the acceleration sensor with a critical value via a signal-comparing unit and hereby judge the collisions under several kinds of conditions. Thus, the system has to be equipped with an accessorial signal-processing part, as a result of which its design is more complicated and inaccurate judgments tends to happen.
The third solution is driving pulse detection, whereby the collision is detected by detecting the waveform of a driving pulse. A rather significant difference exists between a pulse signal in case of a normal running drive motor and that of a collided drive motor, so it is possible to judge whether the collision occurs via detecting any difference of the pulse signal from that of a normal running drive motor. Similar to the acceleration detection, this solution also demands an accessorial signal-processing part, and the design thereof is rather complicated.